As a courtesy to bug-phobes, some of the more lurid images in this post will be hidden until and unless you press this button.
Fear of spiders is based, at least in part, on the fact that a few of them can bite us. When they do, it can hurt. A lot. But did you know spider venom is actually being studied as a painkiller?
Scientists around the globe are looking to venom — from spiders and other sources — as a new, non-addictive drug for blocking pain. Spiders (and other poisonous animals) use their venom to subdue their prey, which can include other arthropods, birds and mammals. Peptides in the venom thereby target a lot of enzymes and cell receptors in a wide range of animals. And this can be exploited for good!
Based on the vast number of spider species (100,000-ish) and the complex nature of their venom, scientists think there could be upward of 12 million types of spider-venom peptides, which could be used for drug research to fight chronic pain. How would this work?
Pain usually means something is wrong, but for people suffering from chronic pain — like from arthritis, cancer or other illnesses — powerful pain blockers are the only thing that help. Some chronic pain relievers block sodium channels, which are pathways in the nervous system that can generate pain signals. One of these blockers is probably familiar: Lidocaine, which you get at the dentist when you have a cavity that needs drilling. But blockers have to target the right channels. Other sodium channels affect your heart and other nerves, and you do not want a painkiller to interfere with those.
That’s where spider peptide comes in. While most pain relief drugs take a shotgun approach, venom-based molecules can zero in on a single channel or enzyme. Though this evolved for the more nefarious purpose of subduing and paralyzing prey, it could also stop pain in its tracks. Researchers are still trying to figure out how to tweak spider venoms to avoid affecting heart function and other muscles, however.
The benefits of spider venom extend beyond pain relief in people. Dr Maggie Hardy at the University of Queensland in Australia is working on spider venom-based treatments for your pets, too. Ticks and fleas are evolving resistance to the common pesticides you might squeeze onto Fido’s back, so new treatments are necessary. Hardy isolated two compounds from the Australian tarantula that show promise for killing fleas and ticks, according to UQ.
Spiders are hardly the only eek animals whose poison can do double-duty as a potent painkiller. Venom from several species of snakes, including the black mamba and the Malayan pit viper, are thought to have beneficial effects. Viper venom has anticoagulant and anti-constriction properties, so it could be used to design blood thinners or drugs that could lower blood pressure. This might help stroke patients and people with hypertension, among others.
More recently, scientists in Australia and China found venom from the red-headed centipede is a more powerful painkiller than morphine, and has no side effects, unlike some spider venoms. So next time you claim to hate all bitey bugs, think twice — they could be more beneficial than you thought.
This very comprehensive review has plenty of detail about spider venoms for therapeutic use.
Description of how centipede venom targets the pain-specific Nav1.7 sodium channel.
More information on sodium channels and pain.